Led bulb adapters and methods of retrofitting led bulbs

ABSTRACT

A method of retrofitting a plurality of LED bulbs to a fluorescent tube fixture with a ballast, a fluorescent tube receptacle, a reflector housing and a lens comprises: removing the lens from the reflector housing; disconnecting the ballast from a mains power supply line and removing the ballast and the fluorescent tube receptacle from the housing. The mains mains power supply is wired to a plurality of Edison socket light-emitting diode (LED) bulb sockets extending from a body defining an electrical junction box and threading a plurality of LED bulbs into the bulb sockets. The electrical junction box is mounted to the reflector housing. The fixture lens is reinstalled to the housing such that the bulb adapter is received in an enclosure defined by the housing and the lens.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/526,141, filed May 11, 2017, which claims priority to International(PCT) Patent Application No. PCT/IB2015/058719, filed Nov. 11, 2015,which claims priority from U.S. Provisional Patent Application No.62/078,161, filed on Nov. 11, 2014, the entire contents of which areincorporated herein by reference.

FIELD

The improvements generally relate to the field of lighting fixtures, andin particular, to LED lighting fixtures.

BACKGROUND

Fluorescent light fixtures are ubiquitous in many applications, such asindustrial, commercial and residential buildings, vessels, and the like.Some building technologies are designed around fluorescent lightfixtures. For example, some types of suspended ceilings are designed toaccommodate fluorescent fixtures of certain standard sizes.

Typical fluorescent light fixtures include a housing and a ballastcircuit, adapted to receive standard mains power such as North Americanstandard 120V/60 Hz AC power, 347V AC power or 277V AC power, as input,and produce suitable output power for driving fluorescent tubes.

Advances in the lighting industry have led to wide availability of manytypes of lightbulbs, including traditional incandescent and fluorescentbulbs, as well as light-emitting diode (LED) bulbs.

LEDs typically provide certain advantages over traditional fluorescentlights. For example, LED lights are typically much more energy efficientand have a longer service life relative to fluorescent and incandescentlights.

Such lights require appropriate fixtures in which to be installed.Unfortunately, some common existing fixture types, such as fluorescenttube fixtures, are not suitable for most LED lights. For example, powerdelivered fluorescent tube fixtures may not be compatible with most LEDlights, and such lights may not produce desirable light distributionwith existing fixtures. Accordingly, retrofitting may be required totake advantage of existing installations.

SUMMARY

Disclosed herein is a method of retrofitting a plurality of LED bulbsconfigured for removable connection to an Edison socket bulb receptacle,to a fluorescent tube fixture having a ballast, a fluorescent tubereceptacle for receiving pins of a fluorescent tube, and an enclosuredefined by a reflector housing and a lens. The method comprises:removing the lens from the reflector housing; disconnecting the ballastfrom a mains power supply line and removing the ballast and thefluorescent tube receptacle from the housing; wiring the mains powersupply line to a plurality of Edison socket light-emitting diode (LED)bulb sockets extending from a body defining an electrical junction box,the bulb sockets configured to distribute light from the LED bulbsacross the lens and the reflector; threading a plurality of LED bulbsinto the bulb sockets; mounting the electrical junction box to thereflector housing; installing the lens to the housing such that the bulbadapter is received in an enclosure defined by the housing and the lens.

Also disclosed herein is a bulb adapter for retrofitting light-emittingdiode (LED) bulbs to a fluorescent tube fixture having a ballast and anenclosure defined by a reflective housing and a lens, the bulb adaptercomprising: a body defining an electrical junction box; a plurality ofLED bulb sockets extending in different directions from the body to holdLED bulbs in a generally planar arrangement inside the enclosure; amounting flange defining an opening in the body for receiving a mainspower supply line to connect the mains power supply line to the LED bulbsockets, the mounting flange for securing the body to the housing sothat the LED bulbs distribute light across the reflective housing andthe lens.

Many further features and combinations thereof concerning embodimentsdescribed herein will appear to those skilled in the art following areading of the instant disclosure.

DESCRIPTION OF THE FIGURES

In the figures which illustrate example embodiments,

FIG. 1 is an exploded view of a flourescent light fixture with tubes;

FIG. 2 is a perspective view of a LED bulb adapter with bulbs;

FIG. 3 is a bottom view of the LED bulb adapter of FIG. 2;

FIG. 4 is a cross-sectional view of the LED bulb adapter of FIG. 3 alongline IV-IV shown in FIG. 3;

FIG. 5 is an exploded view of a light fixture including the LED bulbadapter and bulbs of FIG. 2;

FIG. 6 is a perspective view of another LED bulb adapter;

FIG. 7 is a bottom view of the LED bulb adapter of FIG. 6;

FIG. 8 is a cross-sectional view of the LED bulb adapter of FIG. 6 alongline VIII-VIII shown in FIG. 7;

FIG. 9 is a cross-sectional view of the LED bulb adapter of FIG. 6 alongline IX-IX shown in FIG. 7;

FIG. 10 is an exploded view of another flourescent light fixture withtubes;

FIG. 11 is an exploded view of a light fixture including the LED bulbadapter of FIG. 6 with bulbs;

FIG. 12 is a flow chart depicting a method of retrofitting;

FIG. 13 is a bottom view of an LED bulb adapter with diffusers;

FIGS. 14A-14B are perspective and front views of a diffuser of FIG. 13;

FIG. 15 is a bottom view of another LED bulb adapter with bulbs;

FIG. 16 is a bottom view of a fixture with the LED bulb adapter of FIG.6 and bulbs;

FIG. 17 is a perspective view of an example high-pressure sodium wallpack fixture;

FIG. 18 is a perspective view of a bulb adapter for installation to thewall pack fixture of FIG. 17;

FIG. 19 is a schematic view of an example high pressure sodium lampcircuit; and

FIG. 20 is a schematic view of a bulb arm of an LED bulb adapter.

DETAILED DESCRIPTION

FIG. 1 is an exploded view of an example fluorescent light fixture 100which may, for example, be installed in a commercial or residentialbuilding.

Fluorescent light fixture 100 includes an enclosure defined by a housing101 and a lens 106. Housing 101 includes a top plate 102 and a pluralityof walls 104. Each of top plate 102 and walls 104 has a reflectiveinternal surface. Lens 106 is mounted to housing 101 opposite top plate102. Lens 106 may, for example, be hinged or clipped to walls 104. Lens106 may be transparent or translucent to scatter light. Housing 101 maybe mounted to a ceiling such as a suspended ceiling (not shown). Forexample, housing 101 may be received in a recess in a ceiling. Top plate102 has a hole 108 to receive wiring for driving light fixture 100. Hole108 may be aligned with a junction box 107.

Fluorescent light fixture 100 may be sized to receive fluorescent tubesof a standard length, and in turn, to be received in a lighting recessof a standard size in a wall or ceiling. For example, fluorescent lightfixture 100 may be sized to receive tubes 2, 3, 4 or 8 feet in length,and to be received in a 2 foot by 2 foot, 2 foot by 4 foot, 1 foot by 4foot, 1 foot by 8 foot, 2 foot by 8 foot or 2 foot by 4 foot recess.Fluorescent fixture 100 may also be surface mounted rather than mountedin a recess. Fluorescent tubes may be cylindrical, as depicted.Alternatively, fluorescent tubes may be U-shaped or circular.

Housing 101 of fluorescent light fixture 100 may have a height h definedby walls 104. Height h may be sufficient to so that internal componentsof light fixture 100 may be fully enclosed between housing 101 and lens106. In an example, height h may be 3.5 inches. In other embodiments,height h may be more or less than 3.5 inches.

Fluorescent light fixture 100 has a ballast 110 and a plurality offluorescent tube holders 112. Fluorescent tubes 114 may be installed inlight fixture 100 by mounting in tube holders 112. Though light fixture100 has a single ballast 110, other fixtures may have multiple ballasts,as will be apparent to skilled persons.

Fluorescent tubes 114 may for example be standard mercury-vapor lampswith single-pin or bi-pin connnectors, such as T12, T8 or T5 lamps. Insome embodiments, 114 may be rated for wattage of approximately 30-55watts each. As depicted, four fluorescent tubes 114 are installed infixture 100. However, in other embodiments, more or fewer tubes may bepresent.

Tubes 114 are elongate, and may for example be approximately 4 feet longand 1-2 inches in diameter. Accordingly, as will be apparent, tubes 114distribute light throughout housing 101 and lens 106. The elongate shapeof tubes 114, combined with the reflectivity of the inner surfaces ofhousing 101 and translucency of lens 106 scatters light emanating fromfixture 100 so that a desirable lighting pattern is achieved.

Ballast 110 is wired to mains power, e.g. North American 120V/60 Hz AChousehold power, or 347V AC power through mains power supply lines 116.Ballast 110 is wired to tubes 114 through tube holders 112 and ballastoutput lines 118. Ballast 110 is enclosed within a ballast cover 111 forsafety reasons.

As is well known to skilled persons, ballast 110 converts and conditionsballast input power to safely drive tubes 114. For example, ballast 110provides a start-up voltage to turn on tubes 114 and limits voltage andcurrent through tubes 114 during operation. Tubes 114 typically havecontact pins, which creates a relatively high risk of inadvertent shortcircuit during installation or removal of tubes 114. The fluctuatingvoltage delivered by ballast 110 increases the danger associated withsuch short-circuits and overheating. Safety regulations typicallyrequire that lines carrying mains power (e.g. 120V or 347V) be enclosedwithin ballast cover 111.

Ballast 110 typically consumes power during operation. In an example, aballast 110 for driving T8 fluorescent tubes may consume on the order of10 W and a ballast 110 for driving T12 fluorescent tubes may consume onthe order of 20 W.

LED lamps may be more efficient than typical fluorescent lamps. Forexample, some LED lamps may consume on the order of 70% less power thanfluorescent lamps to produce a corresponding amount of light.

It may therefore be desired to use LED tube lamps with fluorescent lightfixture 100. However, electrical characteristics of typical LED tubesdiffer from those of typical fluorescent tubes. For example, LEDstypically require DC power and different voltage than that required byfluorescent tubes. Thus, use of LED tubes with fixture 100 would requirea specific LED driver instead of or in addition to ballast 110. Suchdrivers are costly and tend to frequently need replacement.

FIG. 2 depicts a perspective view of a lighting assembly 200 configuredfor retrofitting to fixture 100. Lighting assembly 200 includes a LEDbulb adapter 201 and a plurality of high-efficiency bulbs, such as LEDbulbs 220. Lighting assembly 200 allows for the elimination of ballast110 or a separate LED driver and permits safe installation, operationand removal of bulbs. Typically, LED bulbs 220 are rated for 25 W orless. LED bulbs 220 may produce more light per unit wattage thanincandescent or fluorescent lamps. Using relatively low-wattage LEDbulbs (e.g. <25 W) may limit risk of overheating issues. Suitable bulbsare available from numerous manufacturers, such as Philips, GE, Sylvaniaand Cree.

LED bulb adapter 201 has an electrical enclosure 202 and a plurality ofbulb arms 204 which extend away from electrical enclosure 202. Asdepicted, electrical enclosure 202 is an electrical junction box, whichmay be configured and approved to safely house connections between wirescarrying mains (e.g. household 120V AC) power. Electrical enclosure 202is generally rectangular, with four lateral side walls and a top sidehaving a mounting flange 206 defining a central opening 208. However,other shapes are possible.

Bulb arms 204 extend in different directions away from electricalenclosure 202. As depicted in FIGS. 2-4, LED bulb adapter has four bulbarms 204, one extending from each lateral side of the electricalenclosure 202. Bulb arms 204 may be integrally formed with electricalenclosure 202, or may be attached thereto.

In an example, electrical enclosure 202 and bulb arms 204 may be formedfrom a non-flammable and electrically non-conductive material, such aspolyvinyl chloride according to Ontario Provincial StandardSpecification OPSS 2492. Other suitable materials will be apparent toskilled persons.

In some embodiments, LED bulb adapter 201 may be safety certified foruse as an electrical junction box. For example, LED bulb adapter 201 maycarry a certification by UL LLC.

Bulb arms 204 include metallic bulb sockets 222. Bulb sockets 222 haveinternal threads 224 for receiving and releasably retaining bulbs 220.Bulb sockets 222 electrically engage bulbs 220. Bulb sockets 222 may bestandard Edison sockets, such as ANSI or IEC specified standardscrew-type sockets. Such sockets are commonly used for incandescentbulbs. In an example, bulb sockets 222 may be configured to receivebulbs having a standard E26 medium base. Alternatively, bulb sockets 222may be configured to receive bulbs with other standard or non-standardbases. Edison-socket LED bulbs are widely available in many sizes,shapes, wattage ratings, colours, and other variations. Such LED bulbstypically include integrated drivers within the bulb housings forconverting mains (e.g. 120V AC) power to DC power for driving LEDs.

Bulb sockets 222 may be secured to electrical enclosure 202 by fasteners216. Fasteners 216 may be screws or any other suitable fasteners.Fasteners 216 may be received in and engage sockets 227 defined in bulbsockets 222 (see FIG. 4). Bulb sockets 222 may also have a plurality ofterminals 226 for receiving electrical power. As depicted, bulb sockets222 have terminals 226 for connection to positive and negative leads.

Electrical enclosure 202 has a plurality of holes 212 through whichwires 209 may be passed for connection to terminals 226. Electricalenclosure 202 may be positioned with central opening 208 abutting anelectrical connector such as a junction box, and leads from theelectrical junction box may be received through central opening 208 andjoined to leads connected with terminals 226 through openings 212. Thus,electrical enclosure 202 may be mounted within a fixture, defining anelectrical box within the fixture abutting and extending anotherelectrical box outside the fixture. This is contrary to typical lightfixture arrangements, in which the mains connections are enclosedoutside the fixture.

Electrical enclosure 202 is also equipped with a plurality of knock-outpanels 210. Knock-out panels 210 are defined by regions of decreasedwall thickness and can be removed from electrical enclosure 202 bymanual application of pressure to create windows allowing wires to bepassed through.

For example, wiring of some fluorescent fixtures may require mains powersupply lines 116 to be routed other than through a central hole 108 intop panel 102. In such embodiments, power supply wires may be routed toa knock-out rather than through top opening 208. A standard electricalconnector may be mounted at the knock out to allow for a safeconnection, e.g. ½ inch metal or plastic connectors, as are commonlyavailable.

In an example, an extension ring may be fitted over a junction box, anda cable (e.g. a mechanically protected or armored cable) may be run fromthe junction box to an electrical connector in a knock-out. Such anarrangement may be referred to as a “whip” and may permit LED bulbadapter 201 to be placed at any location relative to the junction box.

A plurality of sleeves 214 are defined on the interior of body 214.Sleeves 214 can receive fasteners, e.g. screws, to secure a bottom panel225 to electrical enclosure 202. For the sake of illustration, bottompanel 225 is omitted from FIGS. 3 and 5.

A plurality of mounting holes 207 may be formed in flange 206. Mountingholes may receive screws or other suitable fasteners for attachingelectrical enclosure 202 to a fixture housing, wall or ceiling. In someembodiments, electrical enclosure 202 may be attached using self-tappingscrews. Use of such screws may avoid the need to align mounting holes207 with pilot holes in fixture 100. Mounting holes 207 may bereinforced by tabs 218, formed as regions of flange 206 with increasedthickness. When mounted, mounting flange 206 may tightly abut thesurface to which LED bulb adapter 201 is attached, namely, top panel 102of fixture 100, a wall, a ceiling or the like.

LED bulb adapter 201 may be used to retrofit fixture 100 to use LEDbulbs. FIG. 5 depicts an exploded view of a fixture 300, similar tofixture 100 except that ballast 110, ballast holder 111, tube holder 112and fluorescent tubes 114 have been replaced with LED bulb adapter 201and LED bulbs 220. Like components of fixtures 100, 300 are identifiedwith like numerals.

Mains power supply lines 116 are routed through opening 208 ofelectrical enclosure 202 and connected with bulb sockets 222 throughholes 212. Conveniently, LED bulb adapter 201 encloses mains powersupply lines 116 to protect against shock hazards due to the voltage ofmains power supply lines 116.

As will be apparent from FIG. 5, LED bulb adapter 201 holds LED bulbs220 so that light emitted by LED bulbs 220 is distributed across housing101 and lens 106 of fixture 300. That is, bulb arms 204 extend indifferent directions such that one LED bulb 220 is held proximate eachcorner of housing 101. Thus, light is distributed across the innersurface of housing 101 and reflected toward lens 106, which furtherscatters light exiting the fixture. Accordingly, LED bulb adapter 201may cooperate with housing 101 and lens 106 to achieve lightdistribution similar to that provided by fluorescent tubes 114.

Moreover, while LED bulb adapter holds LED bulbs 220 to cooperate withhousing 101 and lens 106 for effective light distribution, thesubstantially planar configuration of bulb arms 204 limits the height ofLED bulb adapter 201 and the associated bulbs 220, such that they fitentirely within the enclosure defined by housing 101 and lens 106.

Bulb arms 204 may be offset from mounting flange 206 to provide spacingof bulbs 220 from the surface to which LED bulb adapter 201 is mounted.Such spacing may be selected to ensure clearance of certain types of LEDbulbs 220, to ensure that such bulbs fit within the enclosure defined byhousing 101 and lens 106 of fixture 100, and to provide a desired lightdistribution. In an example, an offset O between the top of mountingflange 206 and the midline of bulb arms 204 may be approximately 1 3/16inches.

In an example, each side of electrical enclosure 202 may beapproximately 4 inches long and electrical enclosure 202 may beapproximately 2 4/16 inch thick. Bulb sockets 204 may extendapproximately 1 3/4 inch from electrical enclosure 202 and top opening208 may be approximately 3 inches by 3 inches. The inventors havedetermined that such dimensions ensure acceptable distribution of lightand provide for flexibility of installation.

LED bulb adapter 201 depicted in FIGS. 2-4 has four bulb arms 204 forreceiving four LED bulbs. Other configurations are also possible.

For example, FIGS. 6-7 depict perspective and bottom views,respectively, of a LED bulb adapter 401 having two bulb arms 204 toreceive two LED bulbs.

Bulb arms 204 of LED bulb adapter 401 are identical to bulb arms 204 ofLED bulb adapter 201.

LED bulb adapter 401 has an electrical enclosure 402, generally similarto electrical enclosure 202 of LED bulb adapter 201, but with a narrowerrectangular shape. Bulb arms 204 of LED bulb adapter 401 extend fromopposing ends of electrical enclosure 402 to hold bulbs in a generallyplanar arrangement.

LED bulb adapter 401 is configured for installation to a fluorescentfixture designed to hold two bulbs. In an example, electrical enclosure402 of LED bulb adapter 401 is suited for installation to a fixture 1foot by 4 feet, 1 foot by 8 feet, 2 feet by 2 feet, 2 feet by 4 feet or2 feet by 8 feet.

Electrical enclosure 402 has a mounting flange 406 defining a topopening 408 for receiving mains power supply lines 116 (FIG. 1). Flange406 has a plurality of mounting holes 407 for receiving fasteners suchas screws for fixing electrical enclosure 402 to a fixture, ceiling orwall. Mounting holes are reinforced by tabs 418 formed on flange 406,having increased wall thickness.

Opening 408 is sufficiently large to provide significant clearance forpassing mains power supply lines 116 into electrical enclosure 402. Suchclearance may provide ease and flexibility of installation, aselectrical enclosure 402 need not be precisely aligned.

Electrical enclosure 402 has holes 412 for routing of wires 409 toterminals 224 of bulb arms 204. In addition, electrical enclosure 402has a plurality of knock-out panels 410 defined by regions of decreasedwall thickness, substantially similar to knock-out panels 210.

In an example, LED bulb adapter 401 may have an offset O betweenmounting flange 406 and the midline of bulb arms 204 of approximately 13/16 inches. Electrical enclosure 402 may be approximately 2¼ incheswide and 4 inches long and approximately 2 4/16 inches thick (thicknessrefers to the dimension from mounting flange 206 to bottom panel 225).Top opening 408 may be approximately 3 inches long by 1½ inches wide.

As noted, LED bulb adapter 401 has a narrower body than that of LED bulbadapter 201 and its bulb arms 204 extend away from each end ofelectrical enclosure 402. Thus, LED bulb adapter 401 is well suited forlong and narrow fixtures, such as those designed for holding a pair ofT12 or T8 fluorescent tubes. FIG. 10 shows an exploded view of anexample fixture 100′, identical to fixture 100 except that it is sizedto hold two, rather than four fluorescent tubes 114.

FIG. 11 shows an exploded view of a fixture 300, identical to fixture100′, except that LED bulb adapter 401 and bulbs 220 are retrofitted inplace of ballast 110, ballast cover 111, tube holders 112 andfluorescent tubes 114. LED bulb adapter 401 holds LED bulbs 220 so thatlight emitted by LED bulbs 220 is distributed across the fixture housingand lens. That is, LED bulb adapter 401 holds an LED bulb proximate eachend of such a fixture. Thus, light is distributed across the fixturehousing and reflected toward lens 106, which further scatters lightexiting the fixture.

Moreover, the height and generally planar arrangement of LED bulbadapter 401 permits the bulb adapter and associated bulbs 220 to befully enclosed.

FIG. 12 depicts a method S600 of retrofitting an LED bulb adapter 201,401 and LED bulbs 220 to a fluorescent light fixture 100, 100′.

At block S602, lens 106 is removed from housing 101. Typically, lens 106is secured to housing 101 by one or more clips, in which case the clipsare disengaged. Alternatively, lens 106 may be slid out of housing 101or fasteners holding lens 106 to housing 101 may be removed. In someembodiments, lens 106 may be hingedly attached to housing 101 and mayhang from housing 101 after removal.

Removal of lens 106 provides access to the interior of housing 101.Accordingly, at block S604, tubes 114 may be removed from tube holders112. As noted above, tubes 114 may have a pair of contact pins that arereceived in tube holders 112. Typically, each tube 114 is rotated aboutits longitudinal axis to release its pins from tube holders 112. Oncethe pins are released, the tube 114 is lifted from tube holders 112.

Tubes 114 are removed one at a time. Removal of tubes 114 providesaccess to ballast cover 111.

At block S606, ballast cover 111 is removed. In some embodiments,ballast cover 111 is secured to top plate 102 by clips, which may bereleased to remove ballast cover 111. Alternatively, ballast cover maybe secured to top plate 102 by fasteners such as screws, which may beremoved to remove ballast cover 111. Prior to or following removal ofballast cover 111, power to the fixture may be disconnected, e.g. at acircuit breaker.

At block S608, tube holders 112 are removed from top plate 102 byunfastening screws securing the tube holders to the top plate 102. Oncethe tube holders are unscrewed from top plate 102. Tube holders 112 mayhang from ballast output lines 118 which may still connect tube holders112 to ballast 110.

At block S610, ballast 610 is removed from top late 102 by releasing oneor more clips, removing one or more fasteners, sliding ballast 110 outof a retainer, or a combination thereof. Ballast 110, output lines 118and tube holders 112 are then lifted out of housing 101 as an assembly.

At block S612, mains power supply lines 116 are threaded through topopening 208, 408 and connected to wires 209, 409 to provide power tobulb sockets 222 and thus, to bulbs 220. Connections between mains powersupply lines 116 and wires 209, 409 may be made, for example, using wirenuts. In some cases, each mains power supply line 116 may be connectedto a corresponding wire 209, 409 of more than one contact assembly 222.

If required by the wiring configuration of the fixture to which LED bulbadapter 201, 401 is being retrofitted, a knock-out panel 210, 410 may beremoved and a suitable electrical connector installed in the resultingopening. Mains power supply lines 116 may then be routed through theconnector and knock-out to connect with wires 209, 409.

At block S614, LED bulb adapter 201, 401 is fastened to the fixturehousing by positioning top opening 218, 418 in alignment with hole 108and inserting fasteners, e.g. screws, through mounting holes 207, 407.

At block S616, LED bulbs are threaded into bulb sockets 222.

At block S618, lens 106 is reinstalled to fixture housing 101.

Conveniently, the above-described method may be performed withoutrequiring skilled labor, and with a minimum of tools.

Moreover, in some instances, it may be desired to replace LED bulbs 220.For example, bulbs 220 of different types may be swapped, or defectiveor inoperative bulbs may be replaced with working bulbs. As will beapparent, such replacements may be inexpensive and may be performedmanually without any tools, for example, by a building resident orsuperintendent, without need for an electrician. Conversely, replacing aballast 110 in a fluorescent fixture such as fixture 100 may bedifficult and expensive and may require specialized tools or training.

In some embodiments, one or more diffusers may be mounted to LED bulbadapter 201, 401 to further scatter light produced by LED bulbs 220.FIG. 12 depicts a bottom view of an example LED bulb adapter 201 with adiffuser 228 mounted to each bulb socket 204 to scatter light producedby each respective LED bulb 220.

FIGS. 14A-14B depict a diffuser 228 in isometric view and front views,respectively. Diffuser 228 has a baffle portion 230 and a retaining ring232. Retaining ring 232 is sized to fit tightly over bulb socket 204.Retaining ring 232 is formed of a resiliently deformable material, suchas UL 5VA polyvinyl chloride (PVC). Retaining ring 232 may thus bedeformed slightly to clip over bulb arm 204, and once clipped over bulbarm 204, retaining ring may tightly grip bulb bulb arm 204 to securediffuser 228 thereto.

Baffle portion 230 is formed in a lattice pattern, with grating 234defining a grid of apertures 236. Light produced by LED bulbs 220 maydiffract as it passes through apertures 236, causing scattering of thelight. In an example, each aperture 236 is approximately 2 mm wide and5.5 mm long and grating 234 is approximately 2 mm thick.

Baffle portion 230 may have multiple constituent surfaces, either orboth of which may be inclined and which may be angled relative to oneanother. For example, as best shown in FIG. 14B, baffle portion 230 hastwo surfaces 230-1 and 230-2, each of which is angled at approximately15 degrees to horizontal, and which are angled at approximately 150degrees relative to one another. Angling of surfaces 230-1, 230-2 mayimprove the diffractive effect of diffuser 228.

Grating 236 may have a reflective surface so that light hitting thegrating is reflected and further scattered. For example, grating 236 maybe formed of a metallic material with a shiny finish, or may be paintedor otherwise covered in a white, silver or mirrored coating. Thus,baffle 230 further scatters light produced by LED bulbs 220, such thatwhen installed in a fluorescent fixture, LED bulb adapter 201, 401, LEDbulbs 220 and baffles 230 cooperate with the fixture housing and lens toproduce a diffuse lighting pattern.

Retaining ring 232 is configured to hold baffle portion 230 at aspecific distance from bulb arm 204 (and thus, LED bulb 220) to producethe desired diffractive effect. In an example, retaining ring 232 holdsbaffle portion 230 at a distance of approximately 10 mm below bulb arm204.

Moreover, to ensure that diffuser 228 scatters a sufficient portion ofthe light produced by LED bulb 220, baffle portion 230 may extend aspecific distance beyond the end of bulb arm 204. In an example, baffleportion 230 extends approximately 100 mm past bulb arm 204.

Optionally, baffle portion 230 of diffuser 228 may be pivotally mountedto retaining ring 232 to enable selective repositioning of baffleportion 230 relative to bulb are 204 and bulb 220.

In some embodiments, baffle portion 230 or grating 236 may be formed ina specific shape, such that diffuser 228 cases a shadow and lightingpattern of corresponding shape. For example, baffle portion 230 orgrating 236 may be formed in the shape of a logo, or to create aspecific pattern of light and dark regions.

In some embodiments, LED bulb adapters may have hinged bulb arms. Forexample, FIG. 15 depicts a bottom view of an LED bulb adapter 201′similar to LED bulb adapter 201. LED bulb adapter 201′ has four bulbarms 204′, each of which has a proximal link 240 and a distal link 242,connected by a hinge 244. LED bulbs 220 are received in each distal link242. Each distal link 242 can be pivoted about its respective hinge 244to aim in a desired direction. Thus, LED bulbs 220, and the light theyproduce may be aimed. For example, LED bulbs 220 may be aimed based onthe fixtures to which they are installed to cooperate with the fixturehousing and lens to produce a desired lighting pattern.

In some embodiments, bulb arms may be extendable along or rotatableabout a longitudinal axis. For example, FIG. 20 depicts a bulb arm 204″extending from a body 202″ of an LED bulb adapter 201″. Bulb arm 204″ ispivotable about a hinge 244 in a similar manner to bulb arm 204′. Inaddition, bulb arm has telescoping segments 245 a, 245 b which allowbulb arm 204″ to be extended or retracted along its longitudinal axis L.Telescoping segment 245 b is slidably received by telescoping segment245 a. Segments 245 a, 245 b may be secured relative to one another by aset screw 247 in a guide slot 249.

Moreover, bulb arm 204″ is pivotably mounted to body 202″ such that thebulb arm 204″ can be rotated around its longitudinal axis L. Bulb arm204″ may, for example, be attached to body 202″ by a threadedconnection, such that the threads can hold bulb arm in a range ofpossible orientations.

In some embodiments, rather than being retrofitted to an existingfixture, LED bulb adapters may be provided as part of their ownspecialized fixtures. FIG. 16 depicts a bottom perspective view, inpartial cutaway, of a fixture 1000 with an LED bulb adapter 401 andbulbs 220. Fixture 1000 has an arched top plate 1002 and two opposingend walls 1004. Top plate 1002 and end walls 1004 may be formed of ametallic material such as mild steel and may have reflective innersurfaces. The inner surfaces of top plate 1002 and end walls 1004 may,for example, be painted white or silver, or finished with a mirroredsurface.

Fixture 1002 has an arched lens 1006 defining a light enclosure. Lens1006 may be formed of a translucent plastic or any other suitabletranslucent or transparent material. Lens 1006 may be selected to causerefraction of light produced by LED bulbs 220 to produce a diffuselighting pattern. In the depicted embodiment, fixture 1000 is 2 feetwide by 2 feet long. In other embodiments, fixtures 1000 may have thesame outer dimensions as common fluorescent lighting fixtures.Accordingly, fixtures 1000 may be usable in place of fluorescentfixtures in standard ceiling designs, such as standard suspended ceilingpatterns.

In some embodiments, LED bulb adapters and LED bulbs may be installed inhigh-bay fixtures. For example, some high-bay fluorescent lightingfixtures may be designed to accommodate one or more ballasts, and alarge number of tubes (e.g. 8 or more). Moreover, high-bay fluorescentfixtures may be designed to accommodate relatively high-wattagefluorescent tubes, such as 55W T5 tubes. High-bay fluorescent fixturesmay be designed to be powered by relatively high mains voltage, e.g.347V AC. In such embodiments, multiple LED bulb adapters 201, 401 may beinstalled in a single fixture.

LED bulb adapters 201, 401 may also be installed to fluorescent striplighting fixtures designed to accommodate exposed fluorescent tubes,i.e. to receive flourescent tubes without enclosing them behind a lens.In such fixtures, fluorescent tube holders may be mounted directly to aballast cover. LED bulb adapters 201, 401 may be retrofitted to suchfixtures by removing the tube holders, removing the ballast cover andballast, wiring an LED bulb adapter 201, 401 and attaching it to theballast cover, and re-attaching the ballast cover to the fixture.

In still other embodiments, LED bulb adapters may be installed inhigh-pressure sodium lamp fixtures. For example, FIG. 17 shows a typicalhigh-pressure wall pack fixture 2000. As will be apparent, wall packfixture 2000 is much shorter than fluorescent tube fixture 100.

FIG. 18 shows an example LED bulb adapter 501 configured forinstallation to wall pack fixture 2000. LED bulb adapter 501 is similarto LED bulb adapter 401 except that LED bulb adapter 501 has multiplebulb arms 204 extending from a single side of its body 502, rather thanfrom opposite ends.

FIG. 19 shows a schematic diagram of an electrical configuration of atypical high-pressure sodium wall pack fixture, with a high-pressuresodium lamp 2009 driven by a ballast 2001 and starter 2003 connected toand mains supply lines 2005. To retrofit LED bulb adapter 501, ballast2001, starter 2003 and high-pressure sodium lamp 2009 are disconnectedor disconnected and physically removed. Wires of LED bulb adapter 501are connected to mains supply lines 2005.

In addition to wall-pack high-pressure sodium fixtures, LED bulbadapters may be configured for installation to high-bay high pressuresodium fixtures. Such fixtures may be designed for mounting in a highelevated location above an area to be illuminated. For example, high-bayfixtures may be mounted at an elevation above a warehouse floor.High-bay fixtures designed for high-pressure sodium bulbs may have, forexample downwardly-opening dome, frustoconical or bell shapes and mayinclude a ballast and starter as depicted in FIG. 19. LED bulb adaptersdesigned for such fixtures may have bulb arms that extend downwardly andoutwardly to match the shape of the fixture.

In other embodiments, LED bulb adapters may be installed to other typesof lighting fixtures, such as signage fixtures, pole lamps, and thelike.

The following discussion provides many example embodiments. Althougheach embodiment represents a single combination of inventive elements,other examples may include all possible combinations of the disclosedelements. Thus if one embodiment comprises elements A, B, and C, and asecond embodiment comprises elements B and D, other remainingcombinations of A, B, C, or D, may also be used.

The term “connected” or “coupled to” may include both direct coupling(in which two elements that are coupled to each other contact eachother) and indirect coupling (in which at least one additional elementis located between the two elements).

Although the embodiments have been described in detail, it should beunderstood that various changes, substitutions and alterations can bemade herein.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, manufacture, compositions of matter, means, methods, or steps,presently existing or later to be developed, that perform substantiallythe same function or achieve substantially the same result as thecorresponding embodiments described herein may be utilized. Accordingly,the appended claims are intended to include within their scope suchprocesses, machines, manufacture, compositions of matter, means,methods, or steps

As can be understood, the examples described above and illustrated areintended to be exemplary only. The invention is defined by the appendedclaims.

1. A method of retrofitting a plurality of LED bulbs configured forremovable connection to an Edison socket bulb receptacle, to afluorescent tube fixture having a ballast, a fluorescent tube receptaclefor receiving pins of a fluorescent tube, and an enclosure defined by areflector housing and a lens, the method comprising: removing said lensfrom said reflector housing; disconnecting said ballast from a mainspower supply line and removing said ballast and said fluorescent tubereceptacle from said housing; wiring said mains power supply line to aplurality of Edison socket light-emitting diode (LED) bulb socketsextending from a body defining an electrical junction box, said bulbsockets configured to distribute light from said LED bulbs across saidlens and said reflector; threading a plurality of LED bulbs into saidbulb sockets; mounting said electrical junction box to said reflectorhousing; installing said lens to said housing such that said bulbadapter is received in an enclosure defined by said housing and saidlens.
 2. The method of claim 1, wherein said wiring comprises removing aknock-out panel on said electrical junction box and threading a wirethrough said knock-out panel.
 3. The method of claim 1, furthercomprising attaching said bulb adapter to said reflector housing usingself-tapping fasteners.
 4. The method of claim 1, further comprisingattaching a diffuser grate to at least one of said bulb sockets.
 5. Themethod of claim 1, further comprising threading a non-operative LED bulbout of one of said bulb sockets and threading an operative LED bulb intosaid one of said bulb sockets, wherein said threading is done manuallywithout the use of tools.
 6. The method of claim 1, further comprisingadjusting an orientation of at least one of said bulb sockets to achievea desired light distribution.
 7. (canceled)
 8. (canceled)
 9. The methodof claim 1, wherein said body defining an electrical junction box ismounted inside said housing, opposing another electrical junction boxoutside said housing.
 10. A bulb adapter for retrofitting light-emittingdiode (LED) bulbs to a fluorescent tube fixture having a ballast and anenclosure defined by a reflective housing and a lens, said bulb adaptercomprising: a body defining an electrical junction box; a plurality ofLED bulb sockets extending in different directions from said body tohold LED bulbs in a generally planar arrangement inside said enclosure;a mounting flange defining an opening in said body for receiving a mainspower supply line to connect said mains power supply line to said LEDbulb sockets, said mounting flange for securing said body to saidhousing so that said LED bulbs distribute light across said reflectivehousing and said lens.
 11. The bulb adapter of claim 10, wherein saidbody comprises at least one knock-out panel removable from said body bymanual application of pressure to define a wiring pass-through.
 12. Thebulb adapter of claim 10, wherein said body is formed from a polymer.13. The bulb adapter of claim 12, wherein said body is formed frompolyvinyl chloride (PVC).
 14. The bulb adapter of claim 10, comprising afirst pair of LED bulb sockets extending from said body on oppositesides.
 15. The bulb adapter of claim 11, comprising a second pair of LEDbulb sockets extending from said body on opposite sides, wherein saidfirst pair of LED bulb sockets and said second pair of LED bulb socketsare generally perpendicular to one another.
 16. The bulb adapter ofclaim 10, wherein said bulb sockets are sockets for receiving an LEDbulb with a standard medium size threaded base.
 17. The bulb adapter ofclaim 10, comprising a light diffuser mounted to at least one of saidbulb sockets.
 18. The bulb adapter of claim 16, wherein said lightdiffuser defines a lattice pattern and has a reflective surface.
 19. Thebulb adapter of claim 16, wherein said light diffuser is releasablyattached to said bulb socket with a clip.
 20. The bulb adapter of claim16, wherein said light diffuser has a plurality of inclined diffractivesurfaces at an angle to one another.
 21. A light fixture comprising theadapter of claim 10, mounted within an enclosure defined by a reflectorhousing and a lens.
 22. The bulb adapter of claim 21, wherein said bodydefining an electrical junction box is mounted inside said housing,opposing another electrical junction box outside said housing.